Passive heat exchanger for gimbal thermal management

ABSTRACT

A passive heat exchanger for gimbal thermal management is disclosed. In one embodiment, a thermal management system includes one or more electronics and/or sensor equipment. Further, the thermal management system includes a thermally conductive shell configured to house the electronics and/or sensor equipment. Furthermore, the thermally conductive shell includes an external surface and an internal surface. In addition, at least some portion of the external surface and the internal surface of the thermally conductive shell include an extended surface configured to reduce thermal resistance between an interior region of the thermally conductive shell and ambient air.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims rights under 35 USC §119(e) from U.S. application Ser. No. 61/502,441 filed Jun. 29, 2011, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to cooling systems, more specifically to enclosed volumes containing payloads, such as electronics and sensor equipment.

2. Brief Description of Related Art

One of the most common and important devices found on military host platforms today is a high precision, targetable optical sensor. These sensors are useful for threat detection, weapons targeting, countermeasure functions, surveillance, and many other applications. However, in order to achieve the necessary stability and maneuverability for effective targeting, most such sensors must be attached to a gimbal.

Further, gimbals provide stability and many degrees of freedom, but they require that the optical sensor be encapsulated by a shell. The shell tends to thermally isolate the optical sensor, leaving no direct path from the heat generated by the optical sensor to the exterior of the gimbal. Rather, the heat generated by the optical sensor must overcome three sources of thermal resistance by first transferring from the air to the shell, then transferring through the shell, and finally transferring from the shell to the outside air. This heat transfer scenario represents a relatively poor method for managing the dissipation of a sensor payload.

In such scenarios, the optical sensors can warp and become unreliable in extreme thermal conditions and, as a result, poor thermal management may often limit the environmental conditions in which these optical sensors may reliably operate.

SUMMARY OF THE INVENTION

A passive heat exchanger for gimbal thermal management is disclosed. According to one aspect of the present subject matter, a thermal management system includes one or more electronics and/or sensor equipment. Further, the thermal management system includes a thermally conductive shell configured to house the electronics and/or sensor equipment. Furthermore, the thermally conductive shell includes an external surface and an internal surface. In addition, at least some portion of the external surface and the internal surface of the thermally conductive shell include an extended surface configured to reduce thermal resistance between an interior region of the thermally conductive shell and ambient air.

According to another aspect of the present subject matter, a gimbal includes a thermally conductive sphere configured to house rotatably the electronics and/or sensor equipment. Further, the thermally conductive sphere includes the external surface and the internal surface. Furthermore, the at least some portion of the external surface and the internal surface of the thermally conductive sphere include the extended surface configured to reduce the thermal resistance between an interior region of the thermally conductive sphere and the ambient air.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages and features of the present disclosure will become better understood with reference to the following detailed description and claims taken in conjunction with the accompanying drawings, wherein like elements are identified with like symbols, and in which:

FIG. 1 illustrates an exemplary sectional view of a thermally conductive shell of a gimbal, according to an embodiment of the present subject matter;

FIG. 2 illustrates an exemplary sectional view of a portion of the thermally conductive shell of FIG. 1, according to an embodiment of the present subject matter; and

FIG. 3 illustrates an exemplary isometric view of the gimbal and one or more electronics and/or sensor equipment housed in the thermally conductive shell of FIG. 1, for a thermal management system, according to an embodiment of the present subject matter.

DETAILED DESCRIPTION OF THE INVENTION

The exemplary embodiments described herein in detail for illustrative purposes are subject to many variations in structure and design.

The terms “sphere” and “shell” are used interchangeably throughout the document.

FIG. 1 illustrates an exemplary sectional view 100 of a thermally conductive shell 105 of a gimbal, according to an embodiment of the present subject matter. In one embodiment, the thermally conductive shell 105 is configured to house rotatably one or more electronics and/or sensor equipment. As shown in FIG. 1, the thermally conductive shell 105 includes an external surface 120 and an internal surface 125. Further, at least some portion of the external surface 120 and the internal surface 125 of the thermally conductive shell 105 include an external extended surface 110 and an internal extended surface 115, respectively. In one embodiment, the thermally conductive shell 105 is configured so that when the external extended surface 110 and the internal extended surface 115 are attached to the configured thermally conductive shell forming a complete thermally conductive shell. In another embodiment, the thermally conductive shell 105 is configured such that the external extended surface 110 and the internal extended surface 115 are integral with a remaining portion of the thermally conductive shell 105 without including the extended surfaces. In these embodiments, a material of the thermally conductive shell 105 including the external extended surface 110 and internal extended surface 115 includes aluminum, beryllium, a composite of aluminum and beryllium and the like.

Furthermore as shown in FIG. 1, the external extended surface 110 and the internal extended surface 115 include a plurality of fins. In one exemplary implementation, the fins extend orthogonally or at a slant from the external surface 120 and the internal surface 125 of the thermally conductive shell 105. In one embodiment, the external extended surface 110 and the internal extended surface 115 are configured to reduce thermal resistance between an interior region of the thermally conductive shell 105 and ambient air. Particularly, the fins are configured to reduce the thermal resistance between the interior region of the thermally conductive shell 105 and the ambient air. This is explained in more detailed with reference to FIG. 3.

FIG. 2 illustrates an exemplary sectional view 200 of a portion of the thermally conductive shell 105 of FIG. 1, according to an embodiment of the present subject matter. Particularly, the sectional view 200 illustrates the portion of the thermally conductive shell 105 including the external extended surface 110 and the internal extended surface 115 of the external surface 120 and internal surface 125, respectively. As shown in FIG. 2, the external extended surface 110 and the internal extended surface 115 include a plurality of fins configured to reduce thermal resistance between the interior region of the thermally conductive shell 105 and the ambient air. Further as shown in FIG. 2, the fins extend orthogonally or at a slant from the external surface 120 and the internal surface 125 of the thermally conductive shell 105.

FIG. 3 illustrates an exemplary isometric view 300 of the gimbal and one or more electronics and/or sensor equipment 305 housed in the thermally conductive shell 105 of FIG. 1 for a thermal management system, according to an embodiment of the present subject matter. As shown in FIG. 3, the thermal management system includes the electronics and/or sensor equipment 305 and the thermally conductive shell 105 configured to house the electronics and/or sensor equipment 305. Further, thermally conductive shell 105 includes the external surface 120 and the internal surface 125, such as the one shown in FIG. 1. Furthermore, at least some portion of the external surface 120 and the internal surface 125 of the thermally conductive shell 105 include the external extended surface 110 and internal extended surface 115, respectively. In one embodiment, the thermally conductive shell 105 is configured so that when the external extended surface 110 and the internal extended surface 115 are attached to the configured thermally conductive shell forming a complete thermally conductive shell. In another embodiment, the thermally conductive shell 105 is configured such that the external extended surface 110 and the internal extended surface 115 are integral with a remaining portion of the thermally conductive shell 105 without including the extended surfaces.

In addition as shown in FIG. 3, the external extended surface 110 and the internal extended surface 115 include a plurality of fins. In one exemplary implementation, the fins extend orthogonally or at a slant from the external surface 120 and the internal surface 125 of the thermally conductive shell 105. In one embodiment, the external extended surface 110 and the internal extended surface 115 are configured to reduce thermal resistance between an interior region of the thermally conductive shell 105 and ambient air. Particularly, the fins are configured to reduce thermal resistance between the interior region of the thermally conductive shell 105 and the ambient air.

In operation, the internal extended surface 115 of the thermally conductive shell 105 transfers heat generated by the electronics and/or sensor equipment 305 to a thermally conductive shell wall by providing an increased internal surface area. Further, the generated heat is transferred from the thermally conductive shell wall to the external extended surface 110. In one embodiment, the material of the thermally conductive shell 105 is a highly conductive material which improves the heat transfer through the thermally conductive shell wall. Furthermore, the external extended surface 110 transfers the heat to the ambient air by providing an increased external surface area.

The foregoing descriptions of specific embodiments of the present disclosure have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present disclosure to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present disclosure and its practical application, to thereby enable others skilled in the art to best utilize the present disclosure and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present disclosure. 

1. A thermal management system, comprising: one or more electronics and/or sensor equipment; and a thermally conductive shell configured to house the one or more electronics and/or sensor equipment, wherein the thermally conductive shell includes an external surface and an internal surface, and wherein at least some portion of the external surface and the internal surface of the thermally conductive shell include an extended surface configured to reduce thermal resistance between an interior region of the thermally conductive shell and ambient air.
 2. The thermal management system of claim 1, wherein the thermally conductive shell is configured so that when the extended surface of the external surface and the internal surface is attached to the configured thermally conductive shell forming a complete thermally conductive shell.
 3. The thermal management system of claim 1, wherein the thermally conductive shell is configured such that the extended surface of the external surface and the internal surface is integral with a remaining portion of the thermally conductive shell without including the extended surfaces.
 4. The thermal management system of claim 1, wherein the extended surface of the external surface and the extended surface of the internal surface comprise a plurality of fins, wherein the plurality of fins is configured to reduce the thermal resistance between the interior region of the thermally conductive shell and the ambient air.
 5. The thermal management system of claim 4, wherein the plurality of fins extends orthogonally or at a slant from the external surface and the internal surface of the thermally conductive shell.
 6. The thermal management system of claim 4, wherein a material of the thermally conductive shell including the extended surface of the external surface and the internal surface is selected from the group consisting of aluminum, beryllium, and a composite of aluminum and beryllium.
 7. A gimbal, comprising: a thermally conductive sphere configured to house rotatably one or more electronics and/or sensor equipment, wherein the thermally conductive sphere includes an external surface and an internal surface, and wherein at least some portion of the external surface and the internal surface of the thermally conductive sphere include an extended surface configured to reduce thermal resistance between an interior region of the thermally conductive sphere and ambient air.
 8. The gimbal of claim 7, wherein the thermally conductive sphere is configured so that when the extended surface of the external surface and the internal surface is attached to the configured thermally conductive sphere forming a complete thermally conductive sphere.
 9. The gimbal of claim 7, wherein the thermally conductive sphere is configured such that the extended surface of the external surface and the internal surface is integral with a remaining portion of the thermally conductive sphere without including the extended surfaces.
 10. The gimbal of claim 7, wherein the extended surface of the external surface and the extended surface of the internal surface comprise a plurality of fins, wherein the plurality of fins is configured to reduce thermal resistance between the interior region of the thermally conductive sphere and the ambient air.
 11. The gimbal of claim 10, wherein the plurality of fins extends orthogonally or at a slant from the external surface and the internal surface of the thermally conductive sphere.
 12. The gimbal of claim 10, wherein a material of the thermally conductive sphere including the extended surface of the external surface and the internal surface is selected from the group consisting of aluminum, beryllium, and a composite of aluminum and beryllium. 